🔍 Key Concepts

• Trace the hydraulic lines from item B and see which component it is directly connected to. • Identify what the symbol "PS" at item B usually represents in hydraulic diagrams. • Compare how pump E (local hand pump) and the motor-driven pump at M are supplied and controlled.

💭 Think About

• Does item B supply hydraulic energy, or does it sense a condition and send a control signal? • When the watertight door is fully closed and system pressure rises, which pump would need an automatic stop to prevent overheating or damage? • If pumps F are hand-operated, would they normally require an automatic shutdown device, or just manual control?

✅ Before You Answer

• Verify whether the symbol at B is a pressure switch/sensor or a pump/motor symbol. • Confirm which pump is driven by an electric motor and which is a manual pump, using the symbols near M, E, and F. • Check if any dashed lines from B go toward an electrical or control element associated with the motor-driven pump, indicating a shut-down control rather than a power source.